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AssigneeSensitec GmbH
InventorsJohannes PAUL, Golzar ALAVI, Tsung-I YIN
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A magnetoresistive Wheatstone bridge includes two bridge branches connected in parallel between a supply potential Vb, wherein two series-connected resistor arrangements R1 and R3 or R2 and R4 are arranged in each bridge branch with an interposed measuring potential Vout. The resistor arrangements of the two bridge branches are situated diagonally opposite one another and at least two magnetoresistive resistor arrangements have a magnetically sensitive preferred direction. The preferred directions of diagonally opposing resistor arrangements of the bridge branches R1 and R4 or R2 and R3 differ by an angle other than 0° or 180°. An angle sensor includes at least two of the Wheatstone bridges offset by a predefined angle for determining an angular orientation of a magnetic field by a sine bridge and a cosine bridge. The measuring bridge reduces harmonics and optimizes resistance values, improving the accuracy of a phase-angle sensor signal and the sensor resolution.
Magnetoresistive Wheatstone bridge (10, 12, 14, 16, 18, 20, 22, 24) comprising two bridge branches connected in parallel between a supply potential Vb, two series-connected resistor arrangements R1 and R3 or R2 and R4 being arranged in each bridge branch with an interposed measuring potential Vout, and the resistor arrangements R1 and R4 or R2 and R3 of the two bridge branches being diagonally opposite and at least two magnetoresistive resistor arrangements R1, R2, R3, R4 having a magnetically sensitive preferred direction, characterised in that the preferred directions of diagonally opposing magnetoresistive resistor arrangements of the bridge branches R1 and R4 or R2 and R3 differ from one another by an angle other than 0° or 180°.
Wheatstone bridge (10, 12, 14, 16, 18, 20, 22, 24) according to one of the preceding claims, characterised in that the resistance behaviour of each resistor arrangement R1, R2, R3, R4 is identical in respect of magnitude.
Angle sensor (30) according to one of the preceding claims, characterised in that the resistor arrangements are AMR, GMR, or TMR resistor arrangements, which are arranged on a chip substrate.
Wheatstone bridge (10, 12, 14, 16, 18, 20, 22, 24) according to one of the preceding claims, characterised in that each resistor arrangement R1, R2, R3, R4 comprises a magnetoresistive resistor with a preferred direction, wherein the preferred directions of diagonal opposing resistor arrangements of the bridge branches R1 and R4 or R2 and R3 differ by an angle α from one another, in particular by an angle α=60°.
Wheatstone bridge (10, 12, 14, 16, 18, 20, 22, 24) according to one of the preceding claims, characterised in that, at least in a resistor arrangement R1, R2, R3 or R4, a trimming resistor (50) RXT is series-connected which is preferably selected so as to result in a resistance behaviour identical with regard to magnitude of the resistor arrangements R1, R2, R3 and R4.
Wheatstone bridge (10, 12, 14, 16, 18, 20, 22, 24) according to one of the preceding claims, characterised in that the trimming resistor (50) is a magnetoresistive resistor which has a trimming resistor preferred direction, in particular is a TMR resistor.
Angle sensor (30), characterised in that the angle sensor (30) comprises at least two magnetoresistive Wheatstone bridges (10, 12, 14, 16, 18, 20, 22, 24) offset by a predefined angle, in particular by 90°, according to one of the above-stated claims, for determining an angular orientation of a magnetic field by means of a first and a second sensor bridge (40, 42), in particular a sine bridge and a cosine bridge.
Dependencies are inferred from the claim text.